Data frame with the data arranged and ready to be used by the rest of the ggmcmc functions. The dataframe has four columns, namely: Iteration, Parameter, value and Chain, and six attributes: nChains, nParameters, nIterations, nBurnin, nThin and description.

Name of the family of parameters to plot, as given by a character vector or a regular expression. A family of parameters is considered to be any group of parameters with the same name but different numerical value between square brackets (as beta[1], beta[2], etc).